A Christchurch primary school has bought lifejackets for its children in the event of a tsunami.
South New Brighton School says it is leaving nothing to chance if there is a big earthquake offshore.
The December 23 rupture of a fault line off New Brighton generated 5.3 and 6.0 magnitude quakes in quick succession. They were not enough to cause a tsunami, but experts say two other bigger fault lines further north could trigger 7.0 magnitude-plus quakes, big enough for a tsunami or strong tidal surge.
People near the coastline would have only minutes to escape.
The school, which is only a short distance from the coast, decided to buy more than 400 lifejackets for pupils and staff after reviewing its health and safety policy, principal John Bockett told the Christchurch Star newspaper.
"It really is the same as having lifejackets and flotation devices in aeroplanes - it's just in case," he said.
"We are dealing with lots of precious wee lives and even though the chance of having a localised tsunami is very slim it is important for us to be prepared," he said.
Two families have withdrawn their children from the school since the lifejackets were bought but Mr Bockett said most parents applauded the initiative.
The lifejackets are kept in wheelie bins outside each classroom.
Mr Bockett would not say how much the lifejackets cost but they were purchased with school funds and a donation.
Christchurch City Council has installed 22 tsunami sirens on the coastline and they were tested for the first time last month.